QuickMathand Calc101.comare automatic problem-solving sites that let students enter an expression and get an answer to math problems dealing with polynomial factoring, multiplication, long division, integration and differentiation.

Problem Corner offers mathematics problems for high school and college-level students. It is on the Web site of Southwest Missouri State University’s Department of Mathematics.

Aunty Math - an interactive Web site that encourages students K—5 to submit answers and solution strategies that help solve mathematics challenges.

AAA MATH - a nonprofit web site organized by grade level and subject which offers hundreds of math skills exercises, interactive practice and challenge games on every page, and explanations of math topics.

Figure This! - offers math challenges, including those listed below, that students can do at home. Each challenge features a description of the relevant math involved, notes on how the math can be used outside the classroom, a hint to getting started, and a Try This section.

Tower of Hanoi - offers an interactive logic puzzle called The Tower of Hanoi, in which kids move a tower of rings from one pole to another without placing a larger ring over a smaller one. As kids increase the number of rings, the puzzle becomes more challenging.